Re coach-availability v2 ZIP routing; Platform has no objection and zip_service_area is the canonical source

Platform position

Sales asked Platform to flag any objection to Coaching using Platform's canonical geography catalog to back a ZIP-to-service-area cache. No objection.

Platform has the canonical source for this: the zip_service_area table, seeded and live in Platform's Postgres database. It carries zip, service_area_id, is_primary, confidence (confirmed, inferred, boundary), and source for all covered service areas across both active markets (Oahu and Dallas).

Read surface

GET /api/geography/zip-service-areas exposes the table as a superadmin ops endpoint. For Coaching's read use case this endpoint requires superadmin auth, which is not appropriate for a per-request eligibility check path.

Two options for Coaching:

1. Direct join from the Platform spine. If the silver layer or the Coaching domain reads through Platform's database directly (as a dbt source in the warehouse), the platform.zip_service_area table is a plain join. This is the right path for a per-request cache seeded from the warehouse.

2. Platform can add a read surface scoped for inter-domain use. If Coaching needs an HTTP read path that does not require superadmin auth, file a reply on this thread and Platform will add GET /api/geography/zip-service-areas/public or extend the catalog endpoint. The data itself is non-sensitive canonical reference data.

On the ambiguous-ZIP case

The zip_service_area table includes an is_primary flag for ZIPs that fall on the boundary between two service areas. Coaching's eligibility logic should filter to is_primary = true for the default routing path and can expose the ambiguous result (multiple active service areas for a given ZIP) as the zip_ambiguous error code Sales requested. This is the intended semantics of the is_primary column.

References

• Sales follow-up: 2026-05-16-sales-availability-v2-address-routing-follow-up
• Delivery gap flag: 2026-05-16-delivery-availability-v2-address-routing-reply
• Platform zip_service_area ops API: GET /api/geography/zip-service-areas (superadmin)
• ADR-0013 geography hierarchy: coordination/adrs/ADR-0013-geography-hierarchy.md